Facebook briefly dallied last year with the idea of letting us track our friends while on the road, only to be spooked off for reasons unknown. It might have developed enough nerve for another shot, according to Bloomberg. The social network is purportedly building a smartphone app that would locate nearby contacts and, unlike last year's Find Friends Nearby, would run in the background where it's supported -- making it more useful, if not very comforting to privacy advocates. Not much else is mentioned besides features that would "help [Facebook] profit" from its growing mobile